cdc

The integration question that decides data-platform FDE offers. Log-based vs query-based capture, why deletes break naive designs, the apply-merge that keeps order, and the snapshot step everyone forgets.

CDC design questions usually stop at the happy-path MERGE. This one stress-tests it: an at-least-once stream that double-delivers, hard deletes, soft deletes for audit, and a GDPR erasure that must physically purge even the bronze change log. The guarantees have to compose.

The most common escalation in any data deployment, and the one that quietly ends trust in the platform. Four causes produce it, one of them means nobody is wrong, and you cannot tell them apart without running the ladder in order.

The constraint is the question. It rules out the two approaches most candidates reach for, and the approach that survives has one failure mode that can take the customer's production database down.